SearchViewController 示例

在 Market 项目中发现一个漂亮的搜索页面，记录一下。

SearchViewController.swift:

import UIKit
import NVActivityIndicatorView
import EmptyDataSet_Swift

class SearchViewController: UIViewController {

    //MARK: - IBOutlets
    
    @IBOutlet weak var searchOptionsView: UIView!
    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var searchTextField: UITextField!
    @IBOutlet weak var searchButtonOutlet: UIButton!
    
    //MARK: - Vars
    var searchResults: [Item] = []
    
    var activityIndicator: NVActivityIndicatorView?
    
    
    //MARK: - View Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()

        tableView.tableFooterView = UIView()
        
        searchTextField.addTarget(self, action: #selector(self.textFieldDidChange(_:)), for: UIControl.Event.editingChanged)
        
        tableView.emptyDataSetDelegate = self
        tableView.emptyDataSetSource = self
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        activityIndicator = NVActivityIndicatorView(frame: CGRect(x: self.view.frame.width / 2 - 30, y: self.view.frame.height / 2 - 30, width: 60, height: 60), type: .ballPulse, color: #colorLiteral(red: 0.9998469949, green: 0.4941213727, blue: 0.4734867811, alpha: 1), padding: nil)
    }
    
    
    //MARK: - IBActions
    
    @IBAction func showSearchBarBattonPressed(_ sender: Any) {
        
        dismissKeyboard()
        showSearchField()
    }
    
    @IBAction func searchButtonPressed(_ sender: Any) {
        
        if searchTextField.text != "" {
            
            searchInFirebase(forName: searchTextField.text!)
            emptyTextField()
            animateSearchOptionsIn()
            dismissKeyboard()
        }
        
    }
    
    //MARK: - Search database

    private func searchInFirebase(forName: String) {
        
        showLoadingIndicator()
        
        searchAlgolia(searchString: forName) { (itemIds) in
            
            downloadItems(itemIds) { (allItems) in
                
                self.searchResults = allItems
                self.tableView.reloadData()
                
                self.hideLoadingIndicator()
            }
        }
    }

    
    //MARK: - Helpers
    
    private func emptyTextField() {
        searchTextField.text = ""
    }
    
    private func dismissKeyboard() {
        self.view.endEditing(false)
    }
    
    @objc func textFieldDidChange (_ textField: UITextField) {
        
        searchButtonOutlet.isEnabled = textField.text != ""
        
        if searchButtonOutlet.isEnabled {
            searchButtonOutlet.backgroundColor = #colorLiteral(red: 0.9998469949, green: 0.4941213727, blue: 0.4734867811, alpha: 1)
        } else {
            disableSearchButton()
        }
        
    }
    
    
    private func disableSearchButton() {
        searchButtonOutlet.isEnabled = false
        searchButtonOutlet.backgroundColor = #colorLiteral(red: 0.6666666865, green: 0.6666666865, blue: 0.6666666865, alpha: 1)
    }

    private func showSearchField() {
        
        disableSearchButton()
        emptyTextField()
        animateSearchOptionsIn()
    }
    
    //MARK: - Animations
    
    private func animateSearchOptionsIn() {
        
        UIView.animate(withDuration: 0.5) {
            self.searchOptionsView.isHidden = !self.searchOptionsView.isHidden
        }
    }

    //MARK: - Activity indicator
    
    private func showLoadingIndicator() {
        
        if activityIndicator != nil {
            self.view.addSubview(activityIndicator!)
            activityIndicator!.startAnimating()
        }
    }

    
    private func hideLoadingIndicator() {
        if activityIndicator != nil {
            activityIndicator!.removeFromSuperview()
            activityIndicator!.stopAnimating()
        }
        
    }
    
    private func showItemView(withItem: Item) {
        
        let itemVC = UIStoryboard.init(name: "Main", bundle: nil).instantiateViewController(identifier: "itemView") as! ItemViewController
        
        itemVC.item = withItem
        
        self.navigationController?.pushViewController(itemVC, animated: true)
    }
    
}


extension SearchViewController: UITableViewDataSource, UITableViewDelegate {
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        
        return searchResults.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        
        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! ItemTableViewCell
        
        cell.generateCell(searchResults[indexPath.row])
        
        return cell
        
    }
    
    //MARK: - UITableView Delegate
    
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        
        tableView.deselectRow(at: indexPath, animated: true)
        
        showItemView(withItem: searchResults[indexPath.row])
    }

}


extension SearchViewController: EmptyDataSetSource, EmptyDataSetDelegate {
    
    func title(forEmptyDataSet scrollView: UIScrollView) -> NSAttributedString? {
        
        return NSAttributedString(string: "No itmes to display!")
    }
    
    func image(forEmptyDataSet scrollView: UIScrollView) -> UIImage? {
        return UIImage(named: "emptyData")
    }
    
    func description(forEmptyDataSet scrollView: UIScrollView) -> NSAttributedString? {
        return NSAttributedString(string: "Please check back later")
    }
    
    func buttonImage(forEmptyDataSet scrollView: UIScrollView, for state: UIControl.State) -> UIImage? {
        return UIImage(named: "search")
    }
    
    func buttonTitle(forEmptyDataSet scrollView: UIScrollView, for state: UIControl.State) -> NSAttributedString? {
        return NSAttributedString(string: "Start searching...")
    }
    
    
    func emptyDataSet(_ scrollView: UIScrollView, didTapButton button: UIButton) {
        
        showSearchField()
    }
}

自定义 ItemTableViewCell:

import UIKit

class ItemTableViewCell: UITableViewCell {

    //MARK: IBOutlets
    @IBOutlet weak var itemImageView: UIImageView!
    @IBOutlet weak var nameLabel: UILabel!
    @IBOutlet weak var descriptionLabel: UILabel!
    @IBOutlet weak var priceLabel: UILabel!
    
    
    override func awakeFromNib() {
        super.awakeFromNib()
    }

    override func setSelected(_ selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
    }
    
    func generateCell(_ item: Item) {
        
        nameLabel.text = item.name
        descriptionLabel.text = item.description
        priceLabel.text = convertToCurrency(item.price)
        priceLabel.adjustsFontSizeToFitWidth = true
        
        if item.imageLinks != nil && item.imageLinks.count > 0 {
            
            downloadImages(imageUrls: [item.imageLinks.first!]) { (images) in
                self.itemImageView.image = images.first as? UIImage
            }
        }
    }

}

自定义 Item：

import Foundation
import UIKit
//import InstantSearchClient

class Item {
    
    var id: String!
    var categoryId: String!
    var name: String!
    var description: String!
    var price: Double!
    var imageLinks: [String]!
    
    init() {
    }
    
    init(_dictionary: NSDictionary) {
        
        id = _dictionary[kOBJECTID] as? String
        categoryId = _dictionary[kCATEGORYID] as? String
        name = _dictionary[kNAME] as? String
        description = _dictionary[kDESCRIPTION] as? String
        price = _dictionary[kPRICE] as? Double
        imageLinks = _dictionary[kIMAGELINKS] as? [String]
    }
}


//MARK: Save items func

func saveItemToFirestore(_ item: Item) {
    
    FirebaseReference(.Items).document(item.id).setData(itemDictionaryFrom(item) as! [String : Any])
}


//MARK: Helper functions

func itemDictionaryFrom(_ item: Item) -> NSDictionary {
    
    return NSDictionary(objects: [item.id, item.categoryId, item.name, item.description, item.price, item.imageLinks], forKeys: [kOBJECTID as NSCopying, kCATEGORYID as NSCopying, kNAME as NSCopying, kDESCRIPTION as NSCopying, kPRICE as NSCopying, kIMAGELINKS as NSCopying])
}


//MARK: Download Func
func downloadItemsFromFirebase(_ withCategoryId: String, completion: @escaping (_ itemArray: [Item]) -> Void) {
    
    var itemArray: [Item] = []
    
    FirebaseReference(.Items).whereField(kCATEGORYID, isEqualTo: withCategoryId).getDocuments { (snapshot, error) in
        
        guard let snapshot = snapshot else {
            completion(itemArray)
            return
        }
        
        if !snapshot.isEmpty {
            
            for itemDict in snapshot.documents {
                
                itemArray.append(Item(_dictionary: itemDict.data() as NSDictionary))
            }
        }
        
        completion(itemArray)
    }
    
}

func downloadItems(_ withIds: [String], completion: @escaping (_ itemArray: [Item]) ->Void) {
    
    var count = 0
    var itemArray: [Item] = []
    
    if withIds.count > 0 {
        
        for itemId in withIds {

            FirebaseReference(.Items).document(itemId).getDocument { (snapshot, error) in
                
                guard let snapshot = snapshot else {
                    completion(itemArray)
                    return
                }

                if snapshot.exists {

                    itemArray.append(Item(_dictionary: snapshot.data()! as NSDictionary))
                    count += 1
                }
                
                if count == withIds.count {
                    completion(itemArray)
                }
                
            }
        }
    } else {
        completion(itemArray)
    }
}